title: Accuracy of measurements of crown-rump length and biparietal diameter made by inexperienced operators using a real-time scanner.
mesh_terms: D000886:Anthropometry; D005333:Fetus / Q000033:anatomy & histology*; D005865:Gestational Age; D006801:Humans; D010294:Parietal Bone / Q000196:embryology; D014463:Ultrasonography